Spermiogenesis And the Cycle of The Seminiferous Epithelium in The Platypus, Ornithorhynchus Anatinus.

1998 ◽  
Vol 20 (2) ◽  
pp. 306
Author(s):  
Minjie Lin ◽  
R.C Jones
Keyword(s):  
Biological Sciences ◽  
New South ◽  
Seminiferous Epithelium ◽  
Sperm Production ◽  
Fibrous Sheath ◽  
Dense Granules ◽  
Ultrastructural Studies ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Principal Piece

Department of Biological Sciences, University of Newcastle, New South Wales 2308. Ultrastructural studies of spermiogenesis in platypuses indicate that they display some unique features. The origin and morphology of the perforatorium are different than in sperm from birds and therian mammals, and development of the fibrous sheath of the principal piece starts much later in the platypus. However, some features of spermiogenesis in the platypus are similar to birds, but different from therian mammals. For example, the dense granules in the developing acrosome of therian mammals are absent in platypus spermatids. Other features of spermiogenesis in the platypus are similar to processes described in therian mammals, but not birds. For example, the acrosome of platypus sperm is not confined to the rostral surface of the nucleus as in avian sperm, but extends laterally over the nucleus as in sperm from therian mammals. Further, during spermiation the tubulobulbar complexes were also observed in the platypus. Sixteen steps of spermatid development were identified and used to classify the cycle of the seminiferous epithelium into 12 stages. The area of the wall of a seminiferous tubule, which is occupied by a stage of the cycle of the seminiferous epithelium in the platypus (about 6-8 stages of the cycle per tubular cross-section), is between that of therian mammals (1-4 stages) and birds (up to 12 stages). The cycle ofseminiferous epithelium will provide a basis to determine the rate of sperm production in the platypus.

Morphological observations on the Erthrocytes, Leukocytes and Platelets of Free-Living Platypuses, Ornithorhynchus anatinus (Shaw) (Monotremata : Ornithorhynchidae)

1983 ◽  
Vol 31 (4) ◽  
pp. 421 ◽  
Author(s):  
PJ Canfield ◽  
RJ Whittington
Keyword(s):  
New South ◽  
New South Wales ◽  
Free Living ◽  
Ultrastructural Studies ◽  
South Wales ◽  
Ornithorhynchus Anatinus

Blood was collected from the bill sinus of 10 healthy, mature platypuses captured in the Upper Shoalhaven River of New South Wales. Blood from all 10 animals was used for light microscopic morphometrical studies, and that from four of them was used for ultrastructural studies. The erythrocytes presented no unusual features and were similar to those described for other monotremes, marsupials and man. Platelets were of a mammalian type and uniform. Features of the leukocytes were compared and contrasted with those of other monotremes, marsupials, domestic mammals and man. Unusual features of the leukocytes of the platypus included the consistent presence of Dohle bodies within segmented neutrophils, and the nonsegmented nature of nuclei of eosinophils and basophils. Ultrastructural studies confirmed these findings.

Distribution of the Platypus (Ornithorhynchus anatinus) in New South Wales: Results of The 1994-96 New South Wales Rivers Survey.

1999 ◽  
Vol 21 (2) ◽  
pp. 177
Author(s):  
T.R. Grant ◽  
P.C. Gehrke ◽  
J.H. Harris ◽  
S. Hartley
Keyword(s):  
New South ◽  
New South Wales ◽  
Wide Distribution ◽  
Native Fish ◽  
Coastal Regions ◽  
Community Based ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
The Stability ◽  
Population Numbers

Data from the New South Wales Rivers Survey on the occurrence of platypuses have provided the most recent and comprehensive record of platypus distribution in the State. The species was most commonly reported from the montane and coastal regions, being less common on the western slopes and uncommon in the rivers of the western lowlands. The observations confirmed those from earlier community-based surveys. In contrast to the distribution of native fish species, there appears to have been little change in the overall state-wide distribution of the platypus in response to degrading processes in the rivers of New South Wales, although nothing is known of the stability of their population numbers.

Haematology and Blood Chemistry of the Conscious Platypus, Ornithorhynchus anatinus (Shaw) (Monotremata: Ornithorhynchidae)

1984 ◽  
Vol 32 (5) ◽  
pp. 631 ◽  
Author(s):  
RJ Whittington ◽  
TR Grant
Keyword(s):  
Leukocyte Count ◽  
New South ◽  
Blood Chemistry ◽  
Total Leukocyte Count ◽  
Cell Parameters ◽  
Sexual Dimorphisms ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Serum Biochemical ◽  
The Mean

Blood was collected from a bill sinus of nine conscious adult platypuses, Ornithorhynchus anatinus, caught in south-eastem New South Wales. Sexual dimorphisms were not found in the haematological and serum biochemical values measured. Results were compared with those obtained earlier from anaesthetized platypuses: ether anaethesia did not affect red cell parameters and the majority of biochemical values measured. It did, however, cause significant leukocytosis due to neutrophilia and monocytosis. The mean total leukocyte count in conscious platypuses was 28.63 X 10*9.1-�. The unusually high urea levels and low creatinine levels found in anaesthetized platypus were confirmed in this study (31.5 mmol.l-� and 26 �mol.l-� respectively). High values for erythrocyte count (9.96 X 10*12.l-�), packed cell volume (0.491.l-�) and haemoglobin (190 g.l-�) were found in conscious platypuses, confirming earlier findings and supporting the view that the erythrocyte parameters of the platypus show significant adaptations to hypoxia.

scholarly journals Platypus and Echidnas

1997 ◽  
Vol 3 (2) ◽  
pp. 163 ◽  
Author(s):  
Darren G. Quin
Keyword(s):  
Dna Hybridization ◽  
New South ◽  
Information Source ◽  
Reproductive Physiology ◽  
South Wales ◽  
Veterinary Surgeons ◽  
Ornithorhynchus Anatinus ◽  
Extensive Information ◽  
Phylogeny And Evolution ◽  
The University

Platypus and Echidnas presents the proceedings of a conference held at the University of New South Wales in July 1991. Platypus and Echidnas incorporates an extensive information source obtained from studies undertaken since the first symposium on "Monotreme Biology" in 1978, while highlighting deficiencies in our knowledge, and subsequently suggests further avenues for research. The theme of evolution re-occurs throughout the publication and the studies demonstrate how patterns of mammalian phylogeny may be derived from various sources including palaeontology, gene mapping, DNA hybridization, reproductive physiology and endocrinology. Interest in this publication will extend to: (i) scholars of phylogeny and evolution especially part 1); (ii) comparative physiologist, physiological ecologists and anatomists (parts 1, 3, 4 and 5); (iii) ecologists and sacio-ecologists (parts 3, 5 and 6); (iv) natural historians; (v) keepers of captive wildlife colonies (parts 3 and 6); (vi) wildlife veterinary surgeons (part 6); and (vii) wildlife managers (especially part 6). The book deals primarily with the short-beaked echidna Tachyglossus aculeatus and the platypus Ornithorhynchus anatinus, for which most information is available.

Aspects of Lactation in the Platypus, Ornithorhynchus anatinus (Monotremata), in Waters of Eastern New South Wales.

1983 ◽  
Vol 31 (6) ◽  
pp. 881 ◽  
Author(s):  
TR Grant ◽  
M Griffiths ◽  
RMC Leckie
Keyword(s):  
New South ◽  
New South Wales ◽  
Young Leave ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Significant Difference ◽  
Lactating Females ◽  
One Year ◽  
The One ◽  
First Time

Female platypuses captured in waters of eastern New South Wales were found to be lactating between the months of October and March. Lactating females were most numerous in December, accounting for 64% of females captured. Non-lactating females were taken in all months, indicating that not all females breed successfully every year. There was no significant difference between the fatty acid complement of milk taken from a platypus lactating very late in the season and those of others sampled in December at the peak of the lactation season. Some evidence exists that females do not become reproductive until at least their second year of life. Some females were found lactating in consecutive years, and others lactated one year and not in the one following. Animals of over 9 years of age are known to breed. Most juveniles were captured in February, March and April, and it is suggested that the young leave the breeding burrows for the first time in late January through to March, and become independent from their mothers, who are ceasing lactation at that time.

Platypus, Ornithorhynchus anatinus, Movement Data from The Duckmaloi Weir Pool: Poisson Regression Models.

1998 ◽  
Vol 20 (2) ◽  
pp. 287
Author(s):  
B.A. Ellem ◽  
A. Mcleod
Keyword(s):  
Water Depth ◽  
Poisson Regression ◽  
Regression Models ◽  
New South ◽  
Predictive Variables ◽  
Movement Data ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Potential Benefits ◽  
Foliage Density

McLeod (1993) monitored the movement of platypuses (Ornithorhynchus anatinus) using telemetric devices, recording the number of times animals were found in predetermined grid positions in a pool impounded behind the Duckmaloi Weir near Oberon, New South Wales, and the number of times they were discovered in numerous burrows on the periphery of the weir pool. The aim of this program was to identify the predictive variables that accounted for platypus movement from among those measured such as water depth, and from among known factors such as age. A Poisson regression model is described together with the results for these data. The potential benefits of Poisson regression models for these data over log transformation models, such as handling zeros and catering for overdispersion, are expounded. The analyses indicate that the use of areas of the weir pool were related to water depth, with there being greater use of shallow depths in the channel than in other locations in the pool. There was also differential usage of burrows in the banks of the pool related to different degrees of foliage density from one side of the weir pool to the other.

Distribution of the Platypus (Ornithorhynchus anatinus) in the Bombala River Catchment, South-Eastern New South Wales.

1998 ◽  
Vol 20 (2) ◽  
pp. 251
Author(s):  
R.W. Turnbull
Keyword(s):  
New South ◽  
New South Wales ◽  
River Catchment ◽  
South Eastern ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
The Difference

Distribution of the platypus (Ornithorhynchus anatinus) in the Bombala River catchment in south-eastern New South Wales was surveyed using questionnaires. Platypuses were reported from all streams in the catchment. The majority of positive sightings were from downstream areas whereas very few positive sightings were reported from headwater areas. The difference between frequencies of headwater and downstream reports of sightings was significant. The platypus was considered common throughout the catchment.

Reproductive Seasonality in Female Platypuses, Ornithorhynchus anatinus, in the Upper Barnard River, New South Wales.

1998 ◽  
Vol 20 (2) ◽  
pp. 207
Author(s):  
J.M. Jakubowski ◽  
N.P. New ◽  
G.M. Stone ◽  
R.C. Jones
Keyword(s):  
Blood Plasma ◽  
Seasonal Change ◽  
Coefficient Of Variation ◽  
New South ◽  
Reproductive Seasonality ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Highly Correlated ◽  
Change In Mean ◽  
Mean Concentration

Progesterone concentrations were determined in samples of blood, urine and faeces collected from female platypuses which were captured in the Upper Barnard River, NSW, from February to November, 1996. Mean concentrations in blood plasma were higher in July, August and September than in other months with the highest concentrations being in August. Progesterone concentrations in dried urine and faeces were highly correlated with values for blood plasma (r = 0.61, P<0.05 and 0.7 1, P<O.OI, respectively), and the coefficient of variation for progesterone determinations was lower for samples of urine and faeces than blood. There was a seasonal change in mean concentration of cortisol in blood (being elevated in May-August), but the concentrations of progesterone and cortisol in blood were not significantly correlated.

Population genetics of the platypus (Ornithorhynchus anatinus): a fine-scale look at adjacent river systems

2009 ◽  
Vol 57 (4) ◽  
pp. 225 ◽  
Author(s):  
Stephen H. Kolomyjec ◽  
Josephine Y. T. Chong ◽  
David Blair ◽  
Jaime Gongora ◽  
Tom R. Grant ◽  
...  
Keyword(s):  
Population Genetics ◽  
Isolation By Distance ◽  
New South ◽  
River Systems ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Management Plans ◽  
Discrete Population ◽  
Polymorphic Microsatellite

Population genetics is a powerful tool to increase the understanding of animals that may otherwise be difficult to study, such as the platypus (Ornithorhynchus anatinus). Focusing on two adjacent river systems in New South Wales, we used 12 polymorphic microsatellite loci to investigate the population dynamics of the platypus. We found that individual river systems acted as discrete population units. Evidence of migration, presumably overland, between systems explains how these units remain connected. This establishes an isolation-by-distance pattern that maintains species continuity across most of the mainland distribution. This improved understanding of population structure will be a valuable contribution to designing accurate management plans for the long-term conservation of this unique Australian animal.

The productivity of the macroinvertebrate prey of the platypus in the upper Shoalhaven River, New South Wales

2015 ◽  
Vol 66 (12) ◽  
pp. 1128 ◽  
Author(s):  
R. Marchant ◽  
T. R. Grant
Keyword(s):  
New South ◽  
New South Wales ◽  
Rank Correlation ◽  
Cheek Pouch ◽  
Metabolic Demand ◽  
Energy Demands ◽  
South Wales ◽  
Ornithorhynchus Anatinus ◽  
Order Of Magnitude ◽  
Cheek Pouches

The platypus (Ornithorhynchus anatinus) feeds almost exclusively on benthic macroinvertebrates, yet no attempt has been made to link its energy demands with the productivity of its benthic macroinvertebrate prey. In the upper Shoalhaven River, New South Wales, we estimated macroinvertebrate production (in 2009 and 2011) from benthic samples and recorded platypus diet (2009 only) from cheek pouch samples. Ephemeroptera, Trichoptera and Chironomidae were the most numerous of six major groups in both the cheek pouches and the benthic samples. Three other groups (Odonata, Coleoptera, Sphaeriidae) were much less abundant in the benthos, but Odonata were common in the cheek pouches. In both years the Ephemeroptera, Trichoptera and Chironomidae had levels of production that were an order of magnitude higher than those of the three other groups. Rank correlation indicated that the most productive taxa were those most likely to occur in the cheek pouches. Total macroinvertebrate production for the six groups varied from 7.8gDWm–2year–1 in 2009 to 13.1gDWm–2year–1 in 2011. Previous estimates of field metabolic demand of the platypus enabled calculation of the number that could be supported by a given level of production. The observed levels of production were sufficient to support 13–27 platypuses in 2009 and 22–45 in 2011 along a 1.5-km reach of the river. Despite considerable landscape change, productive foraging habitat persists in the upper Shoalhaven River.

Sign in / Sign up

Export Citation Format

Share Document